Materials including polytetrafluoroethylene (PTFE) are well-known in the art. PTFE has various well-established uses, including, for example, applications requiring lubricity (e.g., bearings, bushings, etc.) and applications requiring a porous membrane. These membrane-related applications may include, for example, filtration, venting, and/or diffusion/barrier applications. Filtration may use discs or sheets. Venting may be particularly useful in automotive-related applications requiring venting, such as, for example, headlamps, electric motors (e.g., for a windshield wiper, etc.), brakes, combustion engines, etc. In addition, healthcare-related applications may also require venting, including, for example, catheters, suction-related apparatuses, instruments, etc. Other venting applications for porous membranes are also known.
It may be beneficial at least in some instances to improve the oleophobicity of PTFE, such that water, oil, and other contaminants may be more effectively repelled by the membrane. See, for example, U.S. Pat. Nos. 5,462,586; 5,554,414; and 6,196,708.